Carbon disulfide has been an important industrial chemical since the nineteenth century. The principal uses of this compound are in the manufacture of regenerated cellulose fibers and films, as a raw material for the manufacture of carbon tetrachloride, as an intermediate in the production of various organic sulfur compounds, and as an organic solvent.
Two methods have been used for the production of carbon disulfide. In one method, a hydrocarbon, particularly in the form of a gas such as methane, ethane or propane, is reacted with sulfur vapors at elevated temperatures in the range of from 600.degree. C. to 750.degree. C. Variations on this basic technique can be found, for example, in U.S. Pat. Nos. 2,809,097, 2,568,121, 2,330,934, 2,492,719 and 2,630,373.
The other method for the production of carbon disulfide involves reacting a solid carbon source with sulfur vapor. When these solid carbon sources are used, the reaction is usually carried out in an externally fired retort wherein sulfur is vaporized and superheated and the reaction between the carbon and sulfur takes place in a reaction vessel containing carbon located on the top of the retort. Internal heat sources also have been used. The preferred solid carbon source has been charcoal although other forms of solid carbon, including lignite, lignite chars, pulverized coal and brown coal semicokes can be used. See, for example, British Pat. No. 705,724 and U.S. Pat. No. 3,402,021.
There has also been a considerable amount of interest in using petroleum coke as a carbon source in this process For instance, U.S. Pat. No. 2,789,037 discloses the use of petroleum coke prepared by the fluid coking process as a solid carbon source for the production of carbon disulfide. The process disclosed in this patent requires a low temperature oxidation pretreatment of the fluid coke used.
In U.S. Pat. No. 2,443,854, there is disclosed a process for the production of carbon disulfide wherein a portion of the powdered carbon is burned to provide the heat necessary for the formation of carbon disulfide. The above patent discloses a reaction chamber comprised of three sections wherein the combustion of the powdered carbon takes place in one section, the vaporized sulfur is fed upwardly so as to react with the combusted powdered carbon in the second section and the carbon disulfide formed is then passed out of this section.
In U.S. Pat. No. 3,034,863, there is disclosed a fluid bed process in which the heat necessary to drive the reaction is supplied from an external source.
In U.S. Pat. No. 2,708,156, an electric furnace for the treatment of petroleum coke is disclosed.
A fluidized bed process for the production of carbon disulfide is also disclosed in U.S. Pat. No. 2,480,639. In the process disclosed in the above patent, the heat for the reaction of carbon and sulfur to produce carbon disulfide is produced by feeding an excess of carbon to the reaction zone, recovering excess unreacted carbon from the reaction zone and recirculating the same to the carbon preheating stage to supply a source of heat for the fresh carbon feed. In another section of the apparatus disclosed in the above patent, a portion of the coke is burned to provide the heat necessary for the carbon disulfide forming reaction.
Both of the above methods do have their respective disadvantages. The recent unavailability of gaseous hydrocarbons has made the use of these compounds as carbon sources in a carbon disulfide production process a rather expensive proposition. Similarly, the high energy costs associated with the internal or external, particularly through electrothermal means, generation of the high temperatures necessary when a solid carbon source is used have also led to increased costs for the use of this process.
Techniques for the production of hydrogen sulfide are also well known (see Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 22, pp. 114-121). One principal use of this compound is in the preparation of inorganic sulfides.